Method of preparing paper



UNITED STATES PATENT OFFIcE.

HENRI PELLET, or rams, FRANCE, ASSIGNOR TO GLARISSE zon JOLTRAIN,

or SAME PLACE.

M ETHOD OF PREPARING PAPER,.&c., FOR REPRODU CING DRAWINGS AND DESIGNS.

SPECIFICATION forming part of Letters Patent No. 241,713, dated May 17, 1881.

Application filed October 25, 1880. (No specimens.) Patented in France November 23, 1877, in Belgium November 26, 1877, and in England December 6, 1877.

To all whom rt may concern: I Be it known that I, HENRI PELLET, of Paris,

in the Republic of France, have invented certain new and useful Improvementsin the Treatment of Paper, Textile and other Fabrics and Materials for Reproducing Patterns and Designs by the Direct Action of Light, of which improvement the following specification is a full description.

The invention has reference to the reproduction upon paper, paper-cloth, cloth, textile and other fabrics .and materials, of drawings, lace and other patterns, devices, or designs which allow light to pass through them unequally in different parts, the surface on which the reproduction is to be effected beingsensitized by a suitable liquor. Heretofore, in order to reproduce designs by the direct action of light, a liquor sensitive to that action is applied to the surface of the pa-,

per or other 'material on which the reproduction is to be efl'ected, and the sensitized sur face is covered with the tracing, piece of lace,

or other suitable material having the design 2 5 formed on or worked into the same and ex-.

posed to the action of light. The portions of sensitized surfacewhich are below the black or opaque parts in the design or pattern are notaffected, but other parts are acted upon by the light transmitted, the liquor being decom:

" posed. In this way a reproduction of the design in white lines upon acolored background has been obtained. The proof is said to be negative. A positive is sometimes obtained 3 5 from this negative, but this involves a double operation and is tedious.

In the present invention a peculiar liquor is employed, characterized by the use of a salt of iron, (ferric salt,) and specially perchloride of 0' iron in connection with an organic acid-such as tartaric, citric, or oxalic acid and gummyor mucilaginous matter. Citric and oxalic acids caualso be used without gummy matter.

'It is an important advantage attending the 5 use of the liquor that with it, by one process,

' designs can be reproduced in dark or colored lines upon a light or] white background.

The sensitizing liquor can he prepared in a numberof ways. The following compositions,

501 which-can beusedsingly or mixed, and in iron can be used in place of the perchloride.

This liquor can be used alone or with thickening substances, such as gelatine, iisinglass, gum, dextrine, glycerine, and other gummy or mucilaginous materials. These can also be ,added in varying proportions in the liquors hereinafter indicated.

Second Type-Perchloride of iron, at 45 Baum, fifteen cubic centimeters; citrate of soda or potassa, eight grams; water to bring the whole to one hundred cubic centimeters.

Third Type.--Perchloride of iron, at 45 Baum, ten per cent; water, ninety per cent. The surface of the article or object on which the reproduction is to be effected is impregnated with the liquid selected, and immediately, or after desiccation, is passed through an alkaline bath, peroxide of iron (ferric oxide) being deposited. The operation of sensitizin gis completed by means of oxalic, citric, or similar acid, or corresponding salts, with or without gummy or mucilaginous substances.

Fourth Typc.0itrate of iron or ammoniacal citrate of iron, three to five grams; 'water to make one hundred centimeters. A solution of citrate of iron has been heretofore used with red prussiate (ferricyanide of potassium) to" obtain white lines on a blue ground. I have discovered that by omitting the red cyanide of potassium and adding a thickening material this new liquor would give the results before I indicated.

Fifth Type.--Pcrchloride of iron, at 45 5 Baum, six to eightcentimeters; tartaric, citric, or similar acid, six to eight grams; ammonia in variable quantities, according to the proportions of othervmaterials; divers thickening or gummy materials in varying proportions. I00

The sensitized paper is prepared by hand, or by amachine with a brush, sponge, or other suitable agent. Having been prepared with the liquor of any of the types before mentioned, it is exposed to light under the drawing, bit of lace, or design to be reproduced. After exposure it is passed through a bath of yellow prussiate, (ferro-cyanide of potassium,) the bath being concentrated or dilute, neutral, slightly acid or slightly alkaline, hot or cold. The parts corresponding to the black portions of the design or pattern become blue. After washing the paper is passed through a dischargingbath (dilute acid or divers salts) and rubbed on its upper surface or not, as may be required.

The operation can be modified. For example, after washing, the paper (without passing through the acid-bath) can be simply rubbed lightly on its surface. The result is a yellow background. The paper can also be passed through an alkaline bath (lime, sucrate of lime, andtother salts in which Prussian blue is soluble,) and then through acid, if desired. The paper used can be blue, colored, silvered, gilded, andwith or without previous designs. To the sensitized liquid there can be added soluble or insoluble colorin g-m atters.

The liquors and methods of operation already indicated can be used on glass, porcelain, metals, wood, and other materials, if it is desired, to obtain photographic negatives.

The, reproduced lines can be brought out, so asto appear blue-black, by the application of twoor more successive layers of a liquor of uniform or varying density for the two layers.

Two layers can also be applied in various other ways; first, by using the acidulated gum and then the perchloride; second, by using the perchloride and then the acidulated gum third, by using the gum alone and then the acidulated perchloride; fourth, by using the acidulated perchloride and then the gum.

Blue-black lines can also be obtained. with a single layer by modifying the proportions of thesalt of iron and the organic acid.

The liquor which is commonly employed by me is composed of, first, gum ten to twelve per cent.; second, salt of iron (perchloride at 45 Baum) eight to twelve per cent. third, citric, tartaric, or similar acid, one and five-tenths to three per cent.

The quantity of gum can be increased according to the paper used and to the atmospheric conditions. The density of the liquor and relative proportions of the gum, salt of iron, and acid should also be modified according to the paper employed, the sensitiveness to be obtained, and the manner of treating the paper.

Another important point to be noticed is that the density should vary with the temperaturev or humidity of the air. In general, the greater the heat the less the density of the liquor.

Instead of wholly immersing the sheet of paper in the bath of prussiate, which furnishes a more or less blue ground, the sheet may be simply floated on the surface. A perfectly white ground can be thus obtained, and less prussiate used. The time required for devel' opment by the prussiate varies with the density of the developing liquid, which should always be as concentrated as possible, and with the accuracy of the placing of the paper. By modifying the thickness of the layer and thequantity of the iron-salt paper can be ob tained of great sensitivenes's, and this can be varied to adapt the papers to different countries and seasons and to various meteorological conditions.

As soon as the design is sufficiently developed by the prussiate the paper is passed through water and a bath of dilute sulphuric, hydrochloric, or other suitable acid or substance. I

The gum my matter is readily detached from the paper, and after immersion fora sufficient time it is separated by a jet of water, all blue parts remaining more or less adherent. The design then appears of a blue-black color. A solid blue-black impression can also beobtained by drying the paper after passing through the bath of prussiate. It is then passed through the water and the,aci d.

Ordinary blue impressions canbe'deepened to blue-black by weak solutions of various alkalies, and byan operation of washing which is discontinued at the proper point. Moreover, blue-black impressions obtained can be made to undergo the modifications which are often effected npon Prussian blue. Forexample, by treating with a dilute solution of soda, washing well, and making the impression black with tannic and other solutions.

With alkalies alone, by contact, longer or shorter, according to thestrength of the solution, a variety of tints can be produced. In the case of paper improperly treated with too little or too much liquor it suffices to pass it (by machine or by hand) through a weak liquor or pure water to restore its properties. Thus there need be no loss of paper in the mann facture. i ,t

The paper can be sensitizedv on the'si'de op= posite the first layer. For particular purposes both surfaces can be treated by one operation or by two, so as to form designson both sides. Thse proofs can be bound into book form.

The blue or black can be strengthened by the addition of a few drops of chlorine-water, nitric acid, or other similar compound to the acid-bath or washing-water. I 1, q

Papers which have been defectively prepared can be restored to their original condition by washing with a roller, or by hand, in water acidulated with hydrochloric, sulphuric,

or other mineral acid, and can, when dry, be

used again.

Having. thus fully explained the said invention, and the manner of carrying the same into effect, what I claim is 1. The method of producing directly,in dark or colored lines, drawings, lacepatterns, and

other devices, by forming upon the surface on which the reproduction is to be efi'ected a sensitized layer containing a salt of iron, asferric salt, and tartaric orother organic acid, afterward exposing'the said layer to light under the pattern or device, and finally developing the parts protected by the opaque or semiopaque portions of the pattern or device with yellow prnssiate of potash, which forms coloring-matter by combining with the unaltered materials of the sensitized layer, substan tially as described.

2. The method of reproducing patterns or designs, by exposing a surface sensitized with a layer of a salt of iron and an organic acid, together with gummy matter, and afterward developing the protected parts of the sensitized layer with yellow prussiate of potash or other suitable chemical liquid, substantially as dc scribed.

3. As a material for reprodncin g designs and patterns directly in dark 1inesby the aid of transmitted light and of a bath for developing of the character indicated a surface sensitized.

with a salt of iron, as ferric salt, and citric or oxalic acid, and afterward developing the sensitive material upon the protected parts by means of yellow prussiate of potash or other chemical liquid which produces colored lines by combining with the said sensitive material, substantially as described.

In testimony whereof Ihave signed my name to this specification before two subscribing witnesses.

H. PELLET.

Witnesses:

ROBT. M. HOOPER, AUG. VINoK. 

